Thomas and friends Wiki

BoCo is a green mixed-traffic diesel engine who primarily works on Edward's Branch Line, and occasionally on the Main Line.


After an initial run-in with Bill and Ben, BoCo has quickly become one of the favorite and funniest diesel engines on the island. Although he must often put up with the antics of Bill and Ben, he has learn to deal with their humor, and at even turns their tricks against them.

BoCo first arrived on Sodor as a visitor on loan, but ended up staying. He had the misfortune to encounter Bill and Ben, who mistook him for a thieving "Diseasel", causing him great confusion. But after having proved to being Really Useful during his stay, the Fat Controller welcomed him as "1 of the family".

BoCo lives at Edward's Station and helps Edward run his Branch Line, but he is always welcomed anywhere. He’s a kind natured diesel with a sense of humour, which makes handling Bill and Ben much easier over the years! Sadly, BoCo is one of the only members of his class left, the other undergoing a long-term restoration at the East Lancashire Railway.

Eventually, BoCo lost his buffer in keeping the twins in line and the Fat Controller decided to bring in a new diesel engine named Derek. Derek (however) had major teething troubles, and was prone to overheating. BoCo had to bring workmen to help Derek when he first broke down, and He somehow made a cameo in the end of Day of the Diesels where he was behind Dart when the Dieselworks was completed.


Although BoCo came across as bullying at first, he was still new to Sodor and turned out to be a good sort who was easy-going and good-natured. He is also said to be the most sensible diesel engines on the Fat Controller's railway and also 1 of the funniest diesel engines on the island.


BoCo is based on a BR Class 28 Co-Bo diesel-electric engine. His name is derived from his Co-Bo wheel arrangement, though reversed as the Reverend W. Awdry thought "BoCo" sounded more affectionate. BoCo was not immune to the mechanical failures of his real-life model, according to the Awdrys - however, the Fat Controller eventually found a fix to prevent this malfunction.

In the annuals, BoCo mentions a brother of his - D5705, a real preserved locomotive. In another annual, BoCo claimed to have a twin called "CoBo" in order to play a trick on Bill and Ben.

BoCo's Basis

(BR Class 28)


BoCo is painted in the green livery of British Railways with yellow warning panels.

In the Television Series, he is painted in a lighter shade of green. The number D5702 is painted on the sides of his cab in white. However, BoCo has a white face to match the other characters.


Railway Series

Television Series

Audio Files

In the 3rd series, BoCo reused Mavis' original horn, but slower and 9 steps lower-pitched.

BoCo's Horn


  • Unlike most of the characters within the Railway Series, BoCo's number was real.
  • Morbidly, the real engine possessing this number was "retired" in 1968 and scrapped the following year.
  • BoCo's name is often misspelled as "Boco".
  • BoCo has had modifications throughout the model era. These include:
    • Series 2-5:
      • His horn is Diesel's at a lower pitch
    • Series 3:
      • His horn is Mavis' original at a lower pitch.
  • In the Railway Series, BoCo has a yellow face whereas in the Television Series, he has a gray one.
  • It is fact that some of Daisy's television series face masks are just BoCo's with added makeup.
  • A book claims that the diesel who came after Thomas' accident was BoCo, but it was really Daisy.


59 Engines | 53 Rolling Stock | 5 Non-Rail Vehicles | 8 People | 15 Lines | 17 Former